Various substituted multicyclic heterocyclic compounds may be useful as pharmaceutical drugs, including inhibitors of the HCV NS5A enzyme. Included in these heterocycles is the tetracyclic heterocyclic core of dimethyl ((2S,2′S)-((2S,2′S)-2,2′-(5,5′-((S)-6-phenyl-6H-benzo [5,6][1,3]oxazino[3,4-a]indole-3,10-diyl)bis(1H-imidazole-5,2-diyl))bis(pyrrolidine-2,1-diyl))bis(3-methyl-1-oxobutane-2,1-diyl))dicarbamate, as defined and described below. These compounds and pharmaceutically acceptable salts thereof may be useful in the treatment or prophylaxis of infection by HCV and in the treatment, prophylaxis, or delay in the onset or progression of HCV infection. Representative tetracyclic heterocyclic compounds that may be useful for treating HCV infection are described, for example, in US Patent Publication No. US20120083483.
US Patent Publication No. US20120083483 discloses methodology that can be employed to prepare such tetracyclic HCV NS5A inhibitors. This general methodology is illustrated immediately below:

The methods described in US Patent Publication No. US20120083483 are practical routes for the preparation of tetracyclic heterocyclic compounds useful as HCV NS5A inhibitors. Nonetheless, there is always a need for alternative preparative routes which, for example, use reagents that are less expensive and/or easier to handle, consume smaller amounts of reagents, provide a higher yield of product, involve fewer steps, have smaller and/or more eco-friendly waste products, and/or provide a product of higher purity or higher enantiomeric excess.